Influence of interwall interaction in double-walled aluminogermanate nanotubes on mechanical properties

Interwall interactions among most existing double-walled nanotubes are governed by van der Waals force, which has a trivial impact on the mechanical properties of the nanotubes. In this work, we investigated double-walled aluminogermanate nanotubes (AlGeNTs) that include surface hydroxyl groups capable of forming interwall hydrogen bonds or being bridged by covalent bonds. Compared to van der Waals force, interwall hydrogen bonds have a much stronger influence on the mechanical properties of nanotubes. We employed molecular dynamics and nanoscale continuum mechanics to estimate the Young's modulus and shear modulus of double-walled AlGeNTs, respectively. We compared the effects of interwall interactions in double-walled AlGeNTs and double-walled carbon nanotubes (CNTs). To amplify the influence of interwall interactions on the elastic modulus of double-walled nanotubes, we also created hypothetical nanotube models in which interwall interactions are represented using covalent bonds. A stronger interwall interaction was shown to increase the Young's modulus of double-walled nanotubes; however, this produced only a marginal improvement in the shear modulus. ? 2017 Elsevier B.V.